ARM: 6244/1: mmci: add variant data and default MCICLOCK support

Add a variant_data structure to handle the differences between the
various variants of this peripheral.  Add a first quirk for a default
MCICLOCK value, required on the Ux500 variant where the enable bit needs
to be always set, since it controls access to some registers.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/mmc/host/mmci.h

@@ -145,6 +145,7 @@
 #define NR_SG		16
 
 struct clk;
+struct variant_data;
 
 struct mmci_host {
 	void __iomem		*base;
@@ -164,6 +165,7 @@ struct mmci_host {
 	unsigned int		cclk;
 	u32			pwr;
 	struct mmci_platform_data *plat;
+	struct variant_data	*variant;
 
 	u8			hw_designer;
 	u8			hw_revision:4;